1. Field of the Invention
The present invention relates to an electrical connecting apparatus suitable for use as an auxiliary device in an electrical test of a semiconductor device such as an integrated circuit.
2. Description of Prior Art
For a test of electric characteristics of an integrated circuit (IC) sealed by a package, a mold or the like, an auxiliary device for testing including an electrical connecting apparatus called socket is generally used. Each electrode of a semiconductor device as a device under test is removably connected with an electric circuit such as a tester. Such an electrical connecting apparatus are described in Patent Document 1 (Japanese Patent Appln. Public Disclosure No. 11-31566 Official Gazette) and Patent Document 2 (Japanese Patent Appln. Public Disclosure No. 2003-297506 Official Gazette).
Each electrical connecting apparatus described in Patent Documents 1 and 2 has a frame with a recess for receiving a device under test formed in the central portion. In the frame, a plurality of contacts called probes are incorporated from the underside of the frame through a rod-like elastic body for elastically supporting the contacts. The contacts are arranged at intervals in the extending direction of each side of the bottom face of the recess such that the tips are projected into the recess from the slot formed on the bottom face of the recess. The semiconductor device as a device under test is mounted within the recess so that its electrode may abut the tips of the corresponding contacts. When pressing force toward the bottom portion of the recess is applied to the semiconductor device mounted on the recess, each contact supported on the elastic body is pressed against the corresponding conductive path of the wiring base plate attached to the underside of the frame. Each conductive path of the wiring base plate is connected to the corresponding connecting terminal of a tester, that is, a device under test, whereby each contact can undergo a predetermined electrical test by the tester when the electric circuit of the tester is connected with each electrode of the device under test.
In the conventional assembling process of the electrical connecting apparatus, a rod-like elastic body for elastically supporting each contact is formed in a lower part of a frame prior to attachment of the wiring base plate to the underside of the frame and inserted into a recess opening downward. The elastic body inserted into the recess is supported at both ends by both end walls of the recess, thereby to be held at a predetermined position. After the assembling of the elastic body into the frame, a plurality of contacts each having a receiving portion for receiving the elastic body formed are inserted into the frame through a corresponding slot from the underside of the frame so that each of the receiving portion may fit the elastic body. After these contacts are assembled, the wiring base plate is attached to the underside of the frame so as to close the open end of the recess accommodating the elastic body, whereby each contact is connected to the corresponding conductive path of the wiring base plate.
However, when any breakage is caused to the contacts and the broken contact should be replaced with a new contact, the wiring base plate must be removed from the frame for the replacement. It is not easy to re-attach the removed wiring base plate correctly to the underside of the frame so that the plural conductive paths formed thereon may match the plural contacts.
Also, in a state that the wiring base plate is removed from the frame, the recess accommodating the elastic body with the plural contacts attached opens downward; therefore, if a flexure occurs to the elastic body whose both ends are elastically supported, there is a risk that both the ends might fall off supporting portions. This falling off of the elastic body from the recess means that all the contacts supported by the elastic body would fall off. Consequently, replacement of the contacts requires a careful treatment so that the elastic body may not fall off the predetermined position while the wiring base plate is being removed from the frame.
Furthermore, the wiring base plate needs to be replaced according to the kind of a tester or the contents of a test by the tester, and a careful treatment is required so that the elastic body holding the plural contacts may not come off the frame every time the wiring base plate is replaced.